Grypania is an early, tube-shaped fossil from the Proterozoic eon. The organism, with a size over one centimeter and consistent form, could have been a giant bacterium, a bacterial colony, or an eukaryoticalga.[2] The oldest probable Grypania fossils date to about 1870 million years ago (redated from the previous 2100 million)[3][4] and the youngest extended into the Ediacaran period.[5] This implies that the time range of this taxon extended for 1200 million years.